Global guidance on environmental life cycle impact assessment indicators: progress and case study

Abstract

Purpose The life cycle impact assessment (LCIA) guidance flagship project of the UNEP/SETAC Life Cycle Initiative aims at providing global guidance and building scientific consensus on environmental LCIA indicators. This paper presents the progress made since 2013, preliminary results obtained for each impact category, and the description of a rice life cycle assessment (LCA) case study designed to test and compare LCIA indicators. MethodsThe effort has been focused in a first stage on impacts of global warming, fine particulate matter emissions, water use and land use, plus cross-cutting issues and LCA-based footprints. The paper reports the process and progress and specific results obtained in the different task forces (TF). Additionally, a rice LCA case study common to all TF has been developed. Three distinctly different scenarios of producing and cooking rice have been defined and underlined with life cycle inventory data. These LCAs help testing impact category indicators which are being developed and/or selected in the harmonisation process. The rice LCA case study further helps to ensure the practicality of the finally recommended impact category indicators. ResultsThe global warming TF concludes that analysts should explore the sensitivity of LCA results to metrics other than GWP. The particulate matter TF attained initial guidance of how to include health effects from PM 2.5 exposures consistently into LCIA. The biodiversity impacts of land use TF suggests to consider complementary metrics besides species richness for assessing biodiversity loss. The water use TF is evaluating two stress-based metrics, AWaRe and an alternative indicator by a stakeholder consultation. The cross-cutting issues TF agreed upon maintaining DALY as endpoint unit for the safeguard subject "human health". The footprint TF defined main attributes that should characterise all footprint indicators. "Rice cultivation" and "Cooking" stages of the rice LCA case study contribute most to the environmental impacts assessed. ConclusionsThe results of the TF will be documented in white papers and some published in scientific journals. These white papers represent the input for the Pellston workshop TM , taking place in Valencia, Spain from 24 to 29 January 2016, where best practice, harmonised LCIA indicators and an update on the general LCIA framework will be discussed and agreed on. With the diversity in results and the multi-tier supply chains the rice LCA case study is well suited to test candidate recommended indicators and to ensure their applicability in common LCA case studies.

Biodiversity impact assessment (BIA+) – methodological framework for screening biodiversity

“…Assessing impacts of products on biodiversity by means of LCA should be considered as a screening method for global impacts on biodiversity. This is in line with Frischknecht and Jolliet (2016), who stated that LCA is restricted to being used for identification of hotspot of impacts on biodiversity only. Afterwards, potential hotspots can be analyzed in greater detail by means of onsite assessments (e.g., environmental impact assessment) by biologists.…”

“…However, we believe that applicable models for including land use change impacts on biodiversity (or rather species diversity) in LCA are available. Even the Life Cycle Initiative recently published a guideline on how to assess land use change impacts on biodiversity (Frischknecht and Jolliet 2016). We do not try to suggest a better methodological framework with regard to land use, but a methodological framework that is easier to apply and covers all levels of biodiversity.…”

Quantifying the climate change effects of bioenergy systems: Comparison of 15 impact assessment methods

“…Despite the dominance of GWPs in LCA studies and carbon footprinting, the application of a wide range of different impact assessment methods between different studies has resulted in ambiguous outcomes and uncertainties, for example, in terms of the climate change mitigation potential of bioenergy systems relative to their fossil fuel counterparts, as demonstrated above. In recent years, however, some progress has been made towards agreed methodology and consistent assessment of climate change impacts, with the work carried out by the IPCC (Plattner et al, ), the European Commission () and the UNEP/SETAC Life Cycle Initiative (Frischknecht & Jolliet, ; Frischknecht et al ., ; Levasseur et al, ) and reviews of proposed approaches (Breton et al, ; Helin et al, ; Røyne et al, ).…”

Timelines for mitigating the methane impacts of using natural gas for carbon dioxide abatement

“…Although most commitments under the Paris Agreement use the GWP(100) to compare CO 2 and non-CO 2 GHGs in CO 2 -equivalent terms, alternative metrics are a subject of active debate in policy and environmental impact research [60,70,84]. For example, recent research has called for reporting CO 2 -equivalent emissions using multiple metrics to better represent the effects of different time horizons, physical and economic impact indicators, and modeling uncertainties [70,71].…”